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Java > Open Source Codes > org > apache > servicemix > locks > impl > SimpleLockManager


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 package org.apache.servicemix.locks.impl;
18
19 import org.apache.servicemix.locks.LockManager;
20
21 import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap;
22 import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentMap;
23 import edu.emory.mathcs.backport.java.util.concurrent.locks.Lock;
24 import edu.emory.mathcs.backport.java.util.concurrent.locks.ReentrantLock;
25
26 public class SimpleLockManager implements LockManager {
27
28     private ConcurrentMap locks = new ConcurrentHashMap();
29     
30     public Lock getLock(String JavaDoc id) {
31         Lock lock = (Lock) locks.get(id);
32         if (lock == null) {
33             lock = new ReentrantLock();
34             Lock oldLock = (Lock) locks.putIfAbsent(id, lock);
35             if (oldLock != null) {
36                 lock = oldLock;
37             }
38         }
39         return lock;
40     }
41
42 }
43
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